LAHORE: Pakistani authorities are investigating allegations that cough syrup has killed 33 people over the past three days, a government official said Saturday, the second time in recent months medicine is suspected of causing multiple deaths.    

The deaths occurred in the eastern city of Gujranwala and nearby villages, said local official Abdul Jabbar Shaheen. Another 54 people thought to have consumed the syrup are also being treated at city hospitals. Officials believe the victims drank the syrup to get high, he added.

Tests show the victims' stomachs contained dextromethorphan, a synthetic morphine derivative used in cough syrup that can have mind-altering effects if consumed in large quantities, said Shaheen. Investigators are trying to determine if the victims drank too much syrup, or whether there was a problem with the medicine itself, he said.

Twenty-three people died in the nearby city of Lahore in November after drinking bad cough syrup sold under the brand name Tyno. They were also described at the time as people who consumed the drug to get high.

Shaheen said the cough syrup involved in the incidents in and around Gujranwala was not sold under a single brand. He said some people in the city make cough syrup to sell specifically to drug addicts, and officials are trying to arrest them.

Officials temporarily closed one Lahore-based pharmaceutical company whose cough syrup was found in the possession of some affected in Gujranwala. They are investigating whether it caused any of the deaths, said Shaheen.